Abstract: An effective seal against the infiltration of foreign matter into a push-pull remote control is provided by a spring-loaded ring seal disposed in contact with a slidable end rod of the control. The ring seal is formed by a plastic C-shaped channel which holds a metal helical spring. One of the two spring-loaded side walls of the C-shaped channel presses against the cylindrical surface of the end rod and thus impedes the penetration of dust and vapors into the remote control.

Abstract: A flexible coupling for rotatable shafts in the form of a metal bellows features a concentric sleeve which is fastened to one end of the coupling and which terminates in a plurality of fingers or keys projecting into, but without contact with, slots in the opposite end of the coupling. In normal use, the coupling transmits rotary motion from one shaft to the other shaft solely through the connecting bellows which provides the flexibility required for small amounts of misalignment and obliqueness of the coupled shafts. If the bellows broke, the concentric sleeve would function as the fail-safe coupling member to continue the transmission of the rotary motion.

Abstract: Flexible remote controls of the type in which at least one push-pull blade extends through a tubular sheath and is supported on its opposite sides by a linear series of spaced balls are improved by placing two linear series of spaced balls in contact with each of the opposite sides of each push-pull blade in the remote control.